A Review on the Use of Artificial Intelligence in Spinal Diseases

Azimi Parisa,Yazdanian Taravat,Benzel Edward C.,Aghaei Hossein Nayeb,Azhari Shirzad,Sadeghi Sohrab,Montazeri Ali 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.4

Artificial neural networks (ANNs) have been used in a wide variety of real-world applications and it emerges as a promising field across various branches of medicine. This review aims to identify the role of ANNs in spinal diseases. Literature were searched from electronic databases of Scopus and Medline from 1993 to 2020 with English publications reported on the application of ANNs in spinal diseases. The search strategy was set as the combinations of the following keywords: “artificial neural networks,” “spine,” “back pain,” “prognosis,” “grading,” “classification,” “prediction,” “segmentation,” “biomechanics,” “deep learning,” and “imaging.” The main findings of the included studies were summarized, with an emphasis on the recent advances in spinal diseases and its application in the diagnostic and prognostic procedures. According to the search strategy, a set of 3,653 articles were retrieved from Medline and Scopus databases. After careful evaluation of the abstracts, the full texts of 89 eligible papers were further examined, of which 79 articles satisfied the inclusion criteria of this review. Our review indicates several applications of ANNs in the management of spinal diseases including (1) diagnosis and assessment of spinal disease progression in the patients with low back pain, perioperative complications, and readmission rate following spine surgery; (2) enhancement of the clinically relevant information extracted from radiographic images to predict Pfirrmann grades, Modic changes, and spinal stenosis grades on magnetic resonance images automatically; (3) prediction of outcomes in lumbar spinal stenosis, lumbar disc herniation and patient-reported outcomes in lumbar fusion surgery, and preoperative planning and intraoperative assistance; and (4) its application in the biomechanical assessment of spinal diseases. The evidence suggests that ANNs can be successfully used for optimizing the diagnosis, prognosis and outcome prediction in spinal diseases. Therefore, incorporation of ANNs into spine clinical practice may improve clinical decision making.

Lumbar Spinal Canal Stenosis Classification Criteria: A New Tool

Parisa Azimi,Hassan Reza Mohammadi,Edward C. Benzel,Sohrab Shahzadi,Shirzad Azhari 대한척추외과학회 2015 Asian Spine Journal Vol.9 No.3

Study Design: Case-control study. Purpose: To design a new tool for classifying lumbar spinal canal stenosis (CLSCS). Overview of Literature: Grading of patients with lumbar spinal canal stenosis (LSCS) is controversial. Methods: The Oswestry disability index (ODI) and the neurogenic claudication outcome score (NCOS) were recorded. Four parameters, which indicate the severity of LSCS disease, including Hufschmidt-grade, grading of magnetic resonance imaging, self-paced walking test, and stenosis ratio (SR) were employed. For the SR, quartile analysis was applied for classifying LSCS and the Hufschmidt- grade was modified into a 4-grade score. An initial score was assigned to each metric based on the severity of LSCS. Using the inverse-variance weighting method, the relative weights of these domains and their categories were determined. The score for all of the cases was obtained based on their weight by summing up the points of the four variables. Quartile analysis was used and a CLSCS score was proposed. Finally, intra- and interobserver reliability, and validity were assessed. Results: A total of 357 patients were studied. The final CLSCS score for each case ranged from 4 to 16.5. Based on the quartile analysis, using the new criteria set, the CLSCS score was divided into four categories: CLSCS<7 (grade 0); 7≤CLSCS<10 (grade 1); 10≤CLSCS<13 (grade 2); and 13≤CLSCS≤16.5 (grade 3). The kappa values of for the CLSCS score indicated a perfect agreement. The CLSCS was correlated with the ODI and NCOS. All patients with grade 3 CLSCS were observed in the surgical group. Conclusions: The CLSCS score can be helpful for classifying LSCS patients and in the decision-making process.

Preliminary Results of Relationship between Preoperative Walking Ability and Magnetic Resonance Imaging Morphology in Patients with Lumbar Canal Stenosis: Comparison between Trefoil and Triangle Types of Spinal Stenosis

Parisa Azimi,Taravat Yazdanian,Edward C. Benzel 대한척추외과학회 2017 Asian Spine Journal Vol.11 No.4

Study Design: Cross-sectional. Purpose: To examine the relationship between magnetic resonance imaging (MRI) morphology stenosis grades and preoperative walking ability in patients with lumbar canal stenosis (LCS). Overview of Literature: No previous study has analyzed the correlation between MRI morphology stenosis grades and walking ability in patients with LCS. Methods: This prospective study included 98 consecutive patients with LCS who were candidates for surgery. Using features identified in T2-weighted axial magnetic, stenosis type was determined at the maximal stenosis level, and only trefoil and triangle stenosis grade types were considered because of sufficient sample size. Intraobserver and interobserver reliability were assessed by calculating weighted kappa coefficients. Symptom severity was evaluated via the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ). Walking ability was assessed using the Self-Paced Walking Test (SPWT) and JOABPEQ subscales. Demographic characteristics, SPWT scores, and JOABPEQ scores were compared between patients with trefoil and triangle stenosis types. Results: The mean patient age was 58.1 (standard deviation, 8.4) years. The kappa values of the MRI morphology stenosis grade types showed a perfect agreement between the stenosis grade types. The trefoil group (n=53) and triangle group (n=45) showed similar preoperative JOABPEQ subscale scores (e.g., low back pain, lumbar function, and mental health) and were not significantly different in age, BMI, duration of symptoms, or lumbar stenosis levels (all p >0.05); however, trefoil stenosis grade type was associated with a decreased walking ability according to the SPWT and JOABPEQ subscale scores. Conclusions: These findings suggest preoperative walking ability is more profoundly affected in patients with trefoil type stenosis than in those with triangle type stenosis.

Cut-off Value for Body Mass Index in Predicting Surgical Success in Patients with Lumbar Spinal Canal Stenosis

Parisa Azimi,Taravat Yazdanian,Sohrab Shahzadi,Edward C. Benzel,Shirzad Azhari,Hossein Nayeb Aghaei,Ali Montazeri 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.6

Study Design: Case-control. Purpose: To determine optimal cut-off value for body mass index (BMI) in predicting surgical success in patients with lumbar spinal canal stenosis (LSCS). Overview of Literature: BMI is an essential variable in the assessment of patients with LSCS. Methods: We conducted a prospective study with obese and non-obese LSCS surgical patients and analyzed data on age, sex, duration of symptoms, walking distance, morphologic grade of stenosis, BMI, postoperative complications, and functional disability. Obesity was defined as BMI of ≥30 kg/m2. Patients completed the Oswestry Disability Index (ODI) questionnaire before surgery and 2 years after surgery. Surgical success was defined as ≥30% improvement from the baseline ODI score. Receiver operating characteristic (ROC) analysis was used to estimate the optimal cut-off values of BMI to predict surgical success. In addition, correlation was assessed between BMI and stenosis grade based on morphology as defined by Schizas and colleague in total, 189 patients were eligible to enter the study. Results: Mean age of patients was 61.5±9.6 years. Mean follow-up was 36±12 months. Most patients (88.4%) were classified with grades C (severe stenosis) and D (extreme stenosis). Post-surgical success was 85.7% at the 2-year follow-up. A weak correlation was observed between morphologic grade of stenosis and BMI. Rates of postoperative complications were similar between patients who were obese and those who were non-obese. Both cohorts had similar degree of improvement in the ODI at the 2-year followup. However, patients who were non-obese presented significantly higher surgical success than those who were obese. In ROC curve analysis, a cut-off value of ≤29.1 kg/m2 for BMI in patients with LSCS was suggestive of surgical success, with 81.1% sensitivity and 82.2% specificity (area under the curve, 0.857; 95% confidence interval, 0.788–0.927). Conclusion: This study showed that the BMI can be considered a parameter for predicting surgical success in patients with LSCS and can be useful in clinical practice.

The Effect of Repetitive Insertion and Pullout of Spinal Screws on Pullout Resistance : A Biomechanical Study

백광흠,김광진,김재민,김충현,Bak, Koang Hum,Ferrara, Lisa,Kim, Kwang Jin,Kim, Jae Min,Kim, Choong Hyun,Benzel, Edward C. The Korean Neurosurgical Society 2001 Journal of Korean neurosurgical society Vol.30 No.2

목적 : 최근 척추 수술에 나사못을 사용하는 빈도와 범위가 넓어 지고 있는데 때로 수술 중 한번 삽입하였던 나사못을 다시 사용하는 경우가 있다. 인체 골과 타이타늄의 탄성계수가 크게 차이 나지만 반복 삽입 과정에서 나사못의 이가 손상될 가능성이 있다. 저자들은 나사못의 반복 삽입이 나사못의 인출 저항에 미치는 영향을 조사하였다. 방법 : 각각 6개의 세가지 다른 종류 cortical lateral mass screw, cancellous lateral mass screw and cervical vertebral body screw의 나사못을 시험하였다. 나사못을 인체의 골과 비슷한 밀도의 인공합성골에 삽입하였으며 삽입 중 삽입력을 측정하였고 그 후 Instron(Model TT-D, Canton, MA)을 이용하여 2.4mm의 속도로 인출하여 인장항력을 digital oscilloscope에 기록하였다. 위의 과정을 3회 반복하여 기록한 뒤 나사못을 광학 현미경으로 확대하여 관찰하였다. 결과 : cortical lateral mass screws의 평균 인장항력(1회인장 시험 $185.66N{\pm}42.60$, 2회 인장시험 $167.10N{\pm}27.01$, 3회인장 시험 $162.52N{\pm}23.83$ : p=0.03)과 cervical vertebral body screws ($386.0N{\pm}24.1$, $360.2N{\pm}17.5$ and $330.9N{\pm}16.7$ : p=0.0024)은 반복하여 삽입, 인장 검사 할 때 마다 감소하였으나 cancellous lateral mass screws의 평균 인장항력($194.00N{\pm}36.47$, $219.24N{\pm}26.58$ and $199.49N{\pm}36.63$ : p=0.24)은 감소하지 않았다. 전자현미경 소견에서 나사이의 끝이 무디어지고 표면이 문드러진 것을 관찰할 수 있었다. 결론 : 일부 나사못을 반복하여 삽입한 후 나사못의 인장항력이 감소되었으므로 수술중 여러번 삽입하였던 나사못은 최종 구조물에 사용되지 않아야 한다. Object : The clinical uses of screws are increasing with broader applications in spinal disorders. When screws are inserted repeatedly to achieve optimal position, tips of screw pitch may become damaged during insertion even though there are significant differences in the moduli of elasticity between bone and titanium. The effect of repeated screw insertion on pullout resistance was investigated. Methods : Three different titanium screws(cortical lateral mass screw, cancellous lateral mass screw and cervical vertebral body screw) were inserted into the synthetic cancellous material and then extracted axially at a rate of 2.4mm/min using Instron(Model TT-D, Canton, MA). Each set of screws was inserted and pulled out three times. There were six screws in each group. The insertional torque was measured with a torque wrench during insertion. Pullout strength was recorded with a digital oscilloscope. Results : The mean pullout force measurements for the cortical lateral mass screws($185.66N{\pm}42.60$, $167.10N{\pm}27.01$ and $162.52 N{\pm}23.83$ for first, second and third pullout respectively : p=0.03) and the cervical vertebral body screws($386.0N{\pm}24.1$, $360.2N{\pm}17.5$ and $330.9N{\pm}16.7$ : p=0.0024) showed consecutive decrease in pullout resistance after each pullout, whereas the cancellous lateral mass screws did not($194.00N{\pm}36.47$, $219.24N{\pm}26.58$ and 199.49N(36.63 : p=0.24). The SEM after insertion and pullout three times showed a blunting in the tip of the screw pitch and a smearing of the screw surface. Conclusions : Repetitive screw insertion and pullout resulted in the decrease of pullout resistance in certain screws possibly caused by blunting the screw tip. This means screw tips suffer deformations during either repeated insertion or pullout. Thus, the screws that have been inserted should not be used for the final construct.